WASHINGTON -- The Supreme Court appeared likely Wednesday to block a group of protesters from bringing free-speech claims against two Secret Service agents who were guarding President George W. Bush during a 2004 visit to Oregon.

The court's liberal justices seemed just as reluctant as the conservatives to find that the agents violated the protesters' First Amendment rights by moving them farther away from the president while allowing a separate group of pro-Bush demonstrators to stay a bit closer.

The protesters claim they were moved for loudly expressing their opinions while Bush was having dinner at an outdoor patio and not for any genuine security reasons.

Deputy Solicitor General Ian Gershengorn argued that agents who make on-the-spot judgments about the president's security should be shielded from liability.

The details

The case is Wood v. Moss, 13-115.

"There are times when we don't want a reasonable official to hesitate before he acts and nowhere is that more important than when the specter of presidential assassination is in order," Gershengorn told the justices.

Justice Antonin Scalia said if there was any objective reason at all for the agents to move protesters to improve security, then "it doesn't matter whether there was any intent to suppress anti-Bush demonstrators."

But Steven Wilker, attorney for the protesters, said his clients were moved solely for expressing their opinions and not for valid security reasons. He said the protesters should be allowed to move ahead with their lawsuit because they presented a valid claim of "viewpoint discrimination" under the First Amendment.

At issue is whether the Secret Service agents should be granted qualified immunity from the lawsuit. Law enforcement agents are typically shielded from liability while performing their official duties. But lawsuits are allowed if the officials' conduct violates clearly established constitutional law.

The dispute began shortly after Bush made a campaign stop in Oregon in the final weeks of his 2004 re-election campaign. At the last minute, the president decided to have dinner in Jacksonville, Ore., at an outdoor patio at the Jacksonville Inn. Secret Service agents cleared the area immediately around the inn, but initially left the protesters in place.

Fifteen minutes after Bush's dinner began, however, the agents ordered police to move the anti-Bush protesters two blocks further away from the inn, placing them at a greater distance from the president than the pro-Bush demonstrators. The agents told police they did not want anyone "within handgun or explosive range of the President."

The protesters claim the difference in where the two groups were allowed to stand shows that they were moved for expressing their opinions in clear violation of their constitutional rights. They say the agents' explanation doesn't ring true because the pro-Bush demonstrators were not moved and other guests of the inn were not screened or removed for weapons.

A federal district court found enough evidence for the case to proceed and the 9th U.S. Circuit Court of Appeals agreed, though eight judges on the appeals court issued a strong dissent.

Justice Elena Kagan asked Wilker if he would concede that a reasonable officer could look at a map of where the protesters were moved and say that it appeared to be a reasonable security measure. Wilker agreed that was "a possible conclusion."

"It seems to me there either is or isn't a valid security interest," Kagan said.

Chief Justice John Roberts suggested viewpoint discrimination could itself be a valid reason for taking security precautions. What if there were an emergency, Roberts asked, and agents had to rush the president out through the anti-Bush crowd or the pro-Bush crowd?

"You have to make a split-second decision," Roberts said. "Which way do you go?"

But other justices didn't seem willing to go that far.

Justice Stephen Breyer said the court wants to draw a line that defers to the need to protect the president, yet avoid giving law enforcement a blank check to run over constitutional rights.

"Everyone understands the danger. You can't run a risk. At the same time, no one wants a Praetorian Guard that is above the law," Breyer said, referring to bodyguards used by Roman emperors.